BYOK (Bring Your Own Key). Your key is kept only in your browser's localStorage — never written to our database, logs, or any other store. On each question, it's sent as an HTTP header which the server forwards directly to Anthropic and streams the response back. You pay Anthropic directly (~$0.003-0.015 per question). Get a free key — new accounts get $5 trial credit, enough for ~500 questions. Click "Forget key" any time to wipe it.